I would pick either the blower or nitrous. Not both. If you do heads/cam and spray you should make enough power to get high 10s. How long the short block and rear end will last, I don't know. That's what I would do, get the heads/cam and spray, and don't be surprised if you break stuff, so the you won't be pissed if/when it happnes lol.

Some of the other, more experienced LS1 guys will probably have a better idea on that, but that's what I'd do.